Magnetic data card servo writer

ABSTRACT

This invention discloses a magnetic servo writer. The magnetic servo writer includes a magnetic pickup head for rotationally moving over and writing servo data in a magnetic flat data-storage medium. The magnetic servo writer further includes a clock head for providing clock signals to the pickup head and to write clock signals in the clock disk. The magnetic servo writer further includes a control circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a servo pattern layout circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium with predefined servo patterns. The magnetic servo writer further includes a derived index control circuit for deriving indices from a fixed index provided on the magnetic flat data-storage medium. The magnetic servo writer further includes a fixed index and clock track circuit for providing a fix index and a clock signal for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a head move circuit for controlling a movement of the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a medium movement circuit for controlling a linear movement of the magnetic flat data-storage medium for writing the servo data on the magnetic flat data-storage medium.

This Application is a Continuous Prosecution Application (CPA) of apending application Ser. No. 09/289,427 filed on Apr. 9, 1999, now U.S.Pat. No. 6,417,980. Application Ser. No. 09/289,427 is aContinuation-in-Part (CIP) Formal Application claims a Priority Date ofApr. 9, 1998, benefited from a previously filed Provisional ApplicationNo. 60/081,257 by the same Applicants of this Application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to systems and method for reading datafrom and writing data to data storage medium by employing the magneticrecording technology. More particularly, this invention is related to animproved magnetic data access system. The data access system isimplemented in a portable data card drive device and in a high speedsubsystem for reading data from and writing data to a magnetic data cardwhich has a novel data track configuration for storing data with uniformdensity. Data can be stored for user applications or related toapplication system configurations.

2. Description of the Prior Art

Conventional technology of reading-writing data on concentric circulardata tracks often presents a problem that the data-bit density variesbetween the outer tracks and the inner tracks. The variable bit densityin data storage is due to a geometrical factor that the outer datatracks are much longer in length than the inner tracks. A commonpractice is to form the inner tracks with a capacity to store the databit at a higher bit density. A more complicate servo control systemimplemented with more complex signal-processing algorithms is requireddue to the variations of data storage density between different datatracks. Additionally, by varying the data storage density from the innertracks toward the outside tracks, the data transfer rate is also changedin accessing data from the inner tracks then outside tracks. Suchvariation may also cause difficulties and complications in processingthe data. Higher error rates may incur due to these variations betweenthe inner tracks and the outer tracks.

Therefore, a need still exists for an improved data-card drive system toovercome the aforementioned difficulties encountered in the prior art.Specifically, this storage card drive system must provide a uniformdensity for data storage and a data-card drive system to access thedata-storage card. Furthermore, it would be desirable that this systemis portable and is also provided with several standardized sizes forprocessing standardized data-storage cards.

SUMMARY OF THE PRESENT INVENTION

Therefore, an object of the present invention is to provide a datastorage-card drive system with a pickup head moving above thedata-storage card in rotational movement. The data read-write functionsare enabled only for arc-segments of the rotational movement such thatthe data tracks are arranged as plurality of parallel arcs, e.g.,half-circles, to overcome the aforementioned difficulties andlimitations encountered in the prior art.

Specifically, it is an object of the present invention to provide adata-storage card drive system with a pickup head driven by a motor,e.g., a brushless motor, to rotate over the data-storage card with therotation axis perpendicular to the card surface. The motor is mounted ona carriage for making horizontal movement along a longitudinal directionof the data card. The position of the pickup head is thenservo-controlled by moving the carriage and the motor while the datastorage card either stays at a fixed position or only pickup head isrotating and the card is making horizontal linear movements.

Another object of the present invention is to provide a data-storagecard drive system for performing the data access tasks over a datastorage medium surface, which has uniform data storage density. A newconfiguration of data-tracks formed as parallel arc or arc-segments,e.g., semi-circular data track, is implemented such that all data trackshave substantially the same length for data storage and the data bitsare stored with uniform density.

Another object of the present invention is to provide a data-storagecard drive device implemented with a subsystem provided with localmemory storage for conveniently interface with personal computers orperipheral devices to achieve higher speed operations.

Briefly, in a preferred embodiment, the present invention discloses amagnetic servo writer. The magnetic servo writer includes a magneticpickup head for rotationally moving over and writing servo data in amagnetic flat data-storage medium. The magnetic servo writer furtherincludes a clock head for providing clock signals to the pickup head andto write clock signals in the clock disk. The magnetic servo writerfurther includes a control circuit for controlling the magnetic pickuphead for writing the servo data on the magnetic flat data-storagemedium. The magnetic servo writer further includes a servo patternlayout circuit for controlling the magnetic pickup head for writing theservo data on the magnetic flat data-storage medium with predefinedservo patterns. The magnetic servo writer further includes a derivedindex control circuit for deriving indices from a fixed index providedon the magnetic flat data-storage medium. The magnetic servo writerfurther includes a fixed index and clock track circuit for providing afix index and a clock signal for controlling the magnetic pickup headfor writing the servo data on the magnetic flat data-storage medium. Themagnetic servo writer further includes a head move circuit forcontrolling a movement of the magnetic pickup head for writing the servodata on the magnetic flat data-storage medium. The magnetic servo writerfurther includes a medium movement circuit for controlling a linearmovement of the magnetic flat data-storage medium for writing the servodata on the magnetic flat data-storage medium.

These and other objects and advantages of the present invention will nodoubt become obvious to those of ordinary skill in the art after havingread the following detailed description of the preferred embodimentwhich is illustrated in the various drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B shows a cross sectional view and a top view respectivelyof a data card drive system of this invention;

FIGS. 1C and 1D are cross sectional views for showing the details of themotor rack mounting and the head loading/unloading assembly;

FIG. 1E shows a perspective view of the pickup head and the wireswinding configuration serving as read/write data signal transformer;

FIGS. 1F and 1G show the top view and cross sectional view respectivelyof a magnetic servo writer of this invention;

FIGS. 2A to 2C are respectively a top view, a cross sectional view and abottom view of a data storage card with data tracks formed for storingbits with uniform density in each of these data tracks;

FIGS. 2D to 2Q show the top views of the data storage card of thisinvention where the data tracks can be arranged in arc-segments ofdifferent shapes, sizes, and facing different directions;

FIGS. 3A and 3B are a perspective view and a cross sectional viewrespectively of a data card storage box;

FIG. 4 is a functional block diagram of a subsystem of this inventionincludes a data card drive device of FIGS. 1A to 1C for reading/writingdata storage card of FIGS. 2A to 2C;

FIGS. 5A and 5B show the data tracks on a magnetic data card with datatracks for writing servo data thereon;

FIG. 5C shows an exemplary pattern of servo data written onto a datatrack;

FIG. 5D shows the position indexes for servo control; and

FIG. 5E is a functional block diagram to illustrate the control logicimplementation of a servo writer of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1A and 1B show a cross sectional view and a top view respectivelyof a data-card drive 100 of the present invention. The data-card drive100 can be configured for reading and writing data-cards of differentsizes, e.g., a PCMCIA type card or common credit card size. Thedata-card can also be of different shapes such as a square, arectangular, a circular disk, or a card with straight and parabolicedges or different types of arc-edges. The data-card drive 100 includesa motor 110, e.g., a DC brushless motor. The motor 110 is provided tooperate at a low speed to conserve battery power, at high speeds toachieve fast data access time. The motor 110 is further provided tofunction at two different modes, i.e., a sleep mode when not beingdeployed, and a wake up mode for normal data access operations. Themotor 110 is mounted on a carriage 115 with a pickup head assemblymounted to the motor rotating shaft assembly. Half of a magnetictransformer, 120-1 which can either being a ring type, a round-disktype, or other geometrical shapes, is mounted onto the motor rotatingshaft assembly, the other half of the magnetic transformer 120-2 ofsimilar configuration is mounted to the fixed part of motor assembly.Signal wires 130 form head are soldered onto the rotating half of thetransformer 120-1 with the soldering pad 125, that can also be a springpressed connection, for transmitting the read/write signals via themagnetic transformer 120. The magnetic transformer 120-1 and thesoldering pad 125 are covered by a magnetic flux shield plate 135 forshielding the magnetic flux generated by the magnetic transformer toprevent DC erase of data. A ground spring 140 is applied to perform thefunction of dissipating electric static discharges. Optionally, abrake-magnet 145 is provided to fix the “parking” position of the motor110 in the sleep or power off mode during the time when there is no dataaccess activities.

A read/write head 150 is mounted via an extended head-arm 152 to thebrushless motor 110 via a head-arm mounting assembly mounting holes 155to the head carriage 115. A head loading/unloading arm 160 is mounted onthe base-plate 170. The loading/unloading arm 160 presses to thehead-arm 152 at the unload position at a drive-device power-off mode.The loading/unloading arm 160 is removed from the head-arm 152 when adata card 180 is loaded and the power for the drive device is turned on.

In order to assist a smooth loading of the data card 180 into the drivedevice 100, a card guide plate 185 is provided. The data-card drivesystem 100 further includes one or several data card pins 190 to engageand fix the position of the data card 180 when the data card 180 reachesa designated operational position. The data card pins 190 increases thecompatibility and interchangeability of different types of data cardsfor data access operations using this data card drive system 100. Thedrive system 100 further includes an on/off switch 195, which is turnedon when the data card 180 reaches its final position.

The brushless motor 110 is mounted onto a motor-rack mount 200 with arack 205 and a pinion 210. A step motor 220 is employed to control thelinear movement of the motor 110 or the movement of the data card 180.The drive device 100 further includes a LCD display 230 to indicate thetrack position of the head 150 in reading or writing of data onto thedata card 180. Mounted on the base plate 170 is a printed circuit board240, which supports a track locator switch 245. The printed circuitboard 240 further supports various kinds of circuits for performing thefunctions of control and data access. These circuits includes headtracking circuit 250, IC preamplifier 255, head loading/unloadingcircuits, disable/enable read-write function circuit, servo controlintegrated circuit (IC), motor control IC, data separator IC, ADIinterface IC, USB interface IC, PCMCIA interface IC, USB connector,PCMCIA connector, and other circuits required for controlling andoperating the data card drive system. FIGS. 1C and 1D are crosssectional views for showing the details of the rack 205, the pinion 210,and the head loading and unloading assembly 160 to lift the head whenthe drive device 100 is turned off. A head arm lifter 103 has a wiretype hook 103A positioned above the pickup head arm 152. The sliding ofthe head arm lifter 103 with the wire type hook 103A along the motorshaft assembly can lift or lower the pickup head arm 152 and in turnlift or lower the pickup head 150. The pickup head arm 152 is rotatingwith the motor shaft and the pickup head 150. Regardless of where thepickup head 150 when the rotational movement stops, the arm 152 canalways engage into the head lifter 103 slot and sliding the head lifter103 along the motor shaft.

The drive device 100 as described above is also provided with an optionto perform the functions of a servo writer. A novel servo writer isdisclosed in this invention which can be manufactured with simplifiedmanufacturing processes. The servo writer includes a storage cardloading assembly that is structured similarly to a card guide 185 of thedevice 100. The storage card can be inserted horizontally inserted fordirect contact with the pickup head 150. Or, depending on specificapplication, the data storage card can be inserted from a vertical slotopening and then flip over for contact with the pickup head. In writingthe servo data, the pickup head 150 is rotating along different datatracks. The pickup head is moved to different tracks during theoperation of writing servo data by either moving the head/motor assemblymounted on the shaft or by keeping the head/motor assembly stationarywhile horizontally moving the data storage card. The magnetictransformer is employed in writing the servo data onto different datatracks where the cables are arranged without being twisted when thepickup head is making rotational movement.

FIGS. 1F and 1G are a top view and a cross sectional view of a preferredembodiment of a data-card servo writer system 100′, which has a clockhead 105 connected to a clock disk 107. The clock disk 107 is disposedbelow the magnetic data card 180 and de-coupled from the data card 180.The motor drives the pickup head 150 also drives the clock disk 107. Theclock disk can be rotated while the clock head 105 is fixed andstationary and mounted on the frame assembly of the servo writer system100′. The clock head 105 is employed to write clock signals, e.g., abinary bit 1 for the whole cycle. All of the data bits on the entiredata track of the clock track are binary bit “1”. Then, a pulse isstopped to write a binary bit “0” to provide that “0” as index whileusing all the bit “1” for timing to format the card. Read and writesignals of the clock head 105 is transmitted through wires to the clockdisk 107 formed on a printed circuit board. The clock head 105 isemployed to write the clock signals onto the magnetic clock disk and toread back the signals. The clock signals read back from the magneticclock disk are used as timing signals to format the card to include theservo patterns to be further described below. Once the magneticdata-card 180 is formatted by the servo-writer system 100′, it is readyfor data read/write operations by applying a regular magnetic data-carddrive system as that shown in FIGS. 1A to 1E. The formatted sectors onthe magnetic data-card 180 are also write-protected to preventincidental writing over these segments. (Do we need to describe writeprotection in some details in order to claim this feature?)

According to FIGS. 1A, 1B, 1C and 1D and above descriptions, the presentinvention discloses a data-card drive system 100 the present inventionincludes a magnetic data-card drive system. The drive system includes amagnetic pickup head for rotationally moving over and accessing datastored in the magnetic data-card. In a preferred embodiment, themagnetic pickup head is provided for reading data from and writing datato the magnetic data card. In another preferred embodiment, the magneticpickup head is provided for accessing data over substantially one-halfof the rotational movement. In another preferred embodiment, themagnetic pickup head is provided for accessing data over severalarc-segments during the rotational movement. In another preferredembodiment, the magnetic pickup head is provided for rotating in asingle rotational direction. In another preferred embodiment, themagnetic pickup head is provided for rotating in clockwise andcounterclockwise directions. In another preferred embodiment, themagnetic pickup head is provided for rotating over arc segment havingradius smaller than half-width of the magnetic data card. In anotherpreferred embodiment, the magnetic pickup head is provided for rotatingover an arc segment having a radius greater than half-width of themagnetic data card. In another preferred embodiment, the magnetic pickuphead is provided as a removable and replaceable module. In anotherpreferred embodiment, the magnetic pickup head is provided for accessingdata by contacting the magnetic data card. In another preferredembodiment, the magnetic pickup head is provided for accessing data byrotating at a distance above the magnetic data card. In anotherpreferred embodiment, the magnetic data-card drive system of furtherincludes a motor that has a rotating shaft for mounting and rotating themagnetic pickup head. In another preferred embodiment, the magneticpickup head further includes a data signal transformer for transforminga data signal through data signal induced changes of magnetic flux.

FIG. 1E is a perspective view of an alternate configuration of a datasignal transformer 120′. The data signal wires 130-1 connected to thepickup head 150′ supported on the arm 152′ for the pickup head 150′ arefirst winding around an inner signal transforming cylinder 122′, whichrotates with the rotation shaft or the motor 110′. A stationary hollowpipe 124′ is placed around the inner signal-transforming cylinder 122′.A set of signal transforming wires wrap around this stationary hollowpipe 124′. For read/write data, an electric signal representing a binarybit can be transferred from a pickup head 150′ through the wires 135′ tothe wires wrapping around the inner signal-transforming cylinder 122′.The electric signals, typically an electric pulse, transferred to thewires around the inner cylinder 122′ can be detected with variations ofelectromagnetic field by a set of wires wrapping around the stationaryhollow pipe 124′. Similarly, the data signal for the pickup head 150′can also be provided to the wires wrapping around the stationary hollowpipe 124′ as electric pulses and detected by the wires wrapping aroundthe inner signal transforming cylinder 122′ for transfer to the pickuphead 150′. The wires around the inner and outer cylindrical pipesfunction as inductive coils serving the function of data signaltransformation.

FIGS. 2A to 2C are respectively a top view, a cross sectional view, anda bottom view of a data card 180 of the present invention. The data card180 is formed on a substrate plate 250. The substrate-plate 250 formagnetic recording is composed of non-magnetizable materials with a flatsurface, e.g., a plastic or glass substrate plate. For magneticrecording, a magnetizable material can also be employed to form thesubstrate plate 250. The substrate plate 250 is then coated with a thinlayer of recording medium on one side or both sides. For magneticrecording, the coating are formed by magnetic particles coated onone-side or both sides of the substrate plate 250. The magnetic coatingcan be directly on the surface of the substrate plate 250 or on a Mylartype of material with adhesive layer for attaching to the substrateplate 250. For magnetic recording the recording medium layer can beformed by a process similar to that of a magnetic compact-disk (CD),CDR, LD, or digital video display (DVD) disks. The data card 180 can beformed with standardized sizes, e.g., PCMCIA standard sizes or standardcredit card sizes, and has round or elongated holes 260 for fixing thecard at pre-designated positions to initialize a data access operation.The holes 260 are fitted to the pins 190 to provide the self-centeringand locking functions. The data storage card 280 can therefore berepeatedly placed at a pre-designated position with reliable accuracy.The data card 180 is provided with a plurality of data tracks 270 forstoring data bit on each track. Each of these data tracks is formed assubstantially an arc or arc-segments track. The data tracks 270 aresubstantially of a same length and are substantially parallel to eachother. The data tracks 270 are formatted to include multiple sectors.One or several of these sectors can be flexibly employed to provideservo data for the purpose of identifying track locations to enhancesector seeking during a data-access operation. The servo-data areprovided in sectors near both ends of the arc or arc-segments datatracks 270 as shown in FIG. 2A. For the purpose of more preciselypositioning the data card 180 in a drive device, a notch 275 is formednear the inner end of the data card 180. With the notch 275, the datacard 180 is more conveniently placed into the drive device fitted to theinitial card position ready for operation relative to the position ofthe pickup head 150. The data card 180 is then covered by a protectivecoating 280 preventing damages from exposure to water, dust and otherforeign particles introduced through the daily operational environment.The data card 180 is then stored in a data card envelop 290 for storageand shipment. The data storage tracks of the data card may contain userapplication and system configuration data. The recorded data can beupdated in the field. Application system can either encrypt or decryptthe recorded data. Application system can also change the configurationsuch as set and reset the write protection, the password and otherfeatures related to the data-access operations.

FIGS. 2D to 2Q are top views of the data storage card 180 for showingdifferent configuration of the data tracks 270. The data tracks 270-1can be parallel arcs facing opposite directions on either side of thedata card 180 as shown in FIG. 2D. Alternately, each of the data tracks270-1 as parallel arc as that shown in FIG. 2D can be partitioned into aplurality of arc-segment 270-2 as that shown in FIG. 2E. In a similarmanner, the data tracks can be parallel arcs 270-3 formed over theentire data card area as that shown in FIG. 2F. Furthermore, each of theparallel arcs 270-3 of FIG. 2F can also be partitioned into a pluralityof arc segments 270-4 as that shown in FIG. 2G.

According to FIGS. 1 to 2, this invention discloses a magneticdata-storage card. The magnetic data-storage card includes a magneticdata-storage medium layer supported on the card. The data-storage mediumlayer includes a plurality of data storage tracks for storing datatherein. Each of the tracks comprising at least an arc-segment whereineach of the data storage track being substantially parallel to aneighboring track. In a preferred embodiment, each of the arc-segmentsare substantially of a same segment length. In a preferred embodiment,the data-storage tracks further storing servo control data. In apreferred embodiment, the data-storage tracks further storing theservo-control data at a substantially same relative position on thedata-storage tracks. In another preferred embodiment, the data-storagetracks further storing the servo-control data near edges of thedata-storage card on the data-storage tracks. In another preferredembodiment, each of the data-storage tracks is substantially asemicircular arc-segment. In another preferred embodiment, each of thedata-storage tracks includes several arc segments. In another preferredembodiment, the magnetic data-storage card further includesself-positioning guiding means for guiding the card to a loadingposition when inserted into a data card drive device. In anotherpreferred embodiment, the magnetic data storage card having a first sideand a second side and the data-storage tracks are disposed on the firstand second sides. In another preferred embodiment, the magnetic datastorage further includes a card jacket for storing the data storagecard.

Furthermore, this invention provides a new method for storing data in amagnetic data-storage card. The method includes the steps of a)providing a magnetic data-storage medium layer supported on thedata-storage card. And, b) forming in the data-storage medium layer aplurality of data storage tracks for storing data therein by formingeach of the tracks to include at least an arc-segment and each of thedata storage tracks substantially parallel to a neighboring track. In apreferred embodiment, the step of forming the data'storage tracks as arcsegments is a step of forming each of the arc segments substantially ofa same segment length. In another preferred embodiment, the methodfurther includes a step of storing servo control data in thedata-storage tracks. In another preferred embodiment, the step ofstoring the servo-control data is a step of storing the servo-controldata at a substantially same relative position on the data-storagetracks. In another preferred embodiment, the step of storing theservo-control data is a step of storing the servo-control data nearedges of the data-storage card on the data-storage tracks. In anotherpreferred embodiment, the step of forming the data-storage to include atleast an arc segment is a step of forming each of the data-storagetracks substantially as a semicircular arc-segment. In another preferredembodiment, the step of forming the data-storage to include at least anarc segment is a step of forming each of the data-storage tracks toinclude several arc segments. In another preferred embodiment, themethod further includes a step of providing a self-positioning guidingmeans for guiding the magnetic data-storage card to a loading positionwhen inserted into a data card drive device. In another preferredembodiment, the step of providing a magnetic data-storage medium layersupported on the card is a step of providing the magnetic data storagecard to include a first side and a second side. And, the step of formingin the data-storage medium layer a plurality of data storage tracks is astep of forming the data-storage tracks on the first and second sides.In another preferred embodiment, the method further includes a step ofproviding a card jacket for storing the data storage card.

FIGS. 3A and 3B are a perspective view and a side view of a data cardstorage rack 295 for storing a plurality of data card 180 therein. Thedata card storage rack 295 as shown can be formed as partitioned storagebox with each compartment ready to receive one data card 180. The datacard storage rack 295 can function as a portable digital camera album ora backup data store for long term data storage.

FIG. 4 shows a subsystem 300 of this invention that includes a data carddrive device 310 identical with the drive device 100 described aboveaccording to FIGS. 1A to 1C. The disk drive device 310 performs the dataaccess tasks on a data storage card 320 identical to the data card 180described above according to FIGS. 2A to 2C. The subsystem 300 furtherincludes a local memory 330, which can be a DRAM or SRAM memory deviceconnected to the disk drive device 310. The data stored in data card 320can be first down loaded to the memory device 330 through a data bus fordata storage. The subsystem 300 further includes a function controlpanel 340 to allow a user to control the subsystem startup, shutdown,save, update, and duplication of the data stored in the card. Thesubsystem 300 is further provided with a connection terminal 350 forconnection to a personal computer, a printer, a scanner or otherperipheral devices for operation together with the drive devicesubsystem 300. A power supply 360 is employed and connected to thesubsystem 300 to provide power necessary for operating the drive device310, the memory 340 and the control panel 330.

Referring to FIGS. 5A to 5C for examples to illustrate the servo signalpatterns written onto the arc segments of the data-storage tracks on adata storage card. FIG. 5A shows the data storage tracks as arcsegments, which may or may not be circular arcs. The servo writer mustwrite servo signals on these data-tracks. Referring to FIG. 5B, thesurface area of the magnetic data-storage card is divided into zones Ato F according to clockwise direction. The servo writer should bedisabled for Zones A, B, D, and E since these zones are not part of thedata tracks. The servo writer must also be disabled in zone E becausethe servo data may be overlapped and create confusions in the process ofpickup head location and track determinations. It is obvious theconventional servo writer and control mechanisms can no longer beemployed for the magnetic data card drive system of this invention.

As shown in FIG. 5A, the length of the data tracks depends on the sizeand dimensions of the data card. Each data track is divided into Nsegments and each segment is provided to contain pre-defined servo data,prerecorded data and/or definitions of area for data records. FIG. 5C isan example of the data arrangements across the tracks of such segment.The total number of data tracks N is determined by the requirements ofthe accuracy of the mechanical and electrical responses. The servo datashown in FIG. 5C can provide the track profile, the location of thetrack and the relative location of signal pickup head to a data trackalong a track.

Referring to the details of data arrangement shown in FIG. 5C, thesignals generated from data bit-patterns A and B are for positiondetermination. Each data track has a half data slots provided for A andhalf of the slots provided for B. The balance of A and B detected by thepickup head and the track location determination circuits provideindications that the pickup head is travelling in the center of the datatrack. Table 1 shows the data sample employed for providing servo datafor track and location determinations as the pickup head is travellingover the surface of the magnetic data storage card.

TABLE 1 Example of Partial Servo Segment Data SYNC 1010101010101010 ADM1000000010000001 ST IDX 11 for First Segment 00 for other segments EDIDX 11 for last segment 00 for other segments A 0000001100000000 B0000000000000011

Referring to FIG. 5D, since the data track can only be arc-segments asthat shown FIG. 5A, the servo writer must start and stop to layoutpatterns at pre-determined locations. An index is used as a referencepoint at a fixed location on the magnetic data-storage card. Thestarting point SX and the stopping position EX of the servo data arederived from the reference point IX as shown in FIG. 5D. A servo controlcircuit is employed to enable and disable the pattern layout process andto move the magnetic pickup head and the flat data-storage medium, i.e.,the magnetic data storage card by using the feedback by detecting thesethree indices. An exemplary functional block diagram for implementingthe control logic in the servo control circuit is shown in FIG. 5E.

According to FIGS. 5A to 5E, this invention discloses a magnetic servowriter. The magnetic servo writer includes a magnetic pickup head forrotationally moving over and writing servo data in a magnetic flatdata-storage medium. The magnetic servo writer further includes a clockhead for providing clock signals to the pickup head and to write clacksignals in the clock disk. The magnetic pickup head is provided forwriting SYNC data for synchronization of read channel, and ADM data forproviding address mark for indicating data-types following the ADM data.The magnetic pickup head is provided for writing ST IDX data forindicating a first valid data segment, ED IDX data for indicating a lastvalid data segment, and GRAY CODE data for indicating a head number, asector number, and a track number. Furthermore, the magnetic pickup headis provided for writing SERVO POS data for indicating a relativeposition of signal head to a data track, DATA & GAP data for indicatingan area for containing pre-recorded data. In a preferred embodiment, themagnetic pickup head is provided for writing index data for indicating avalid data track segment.

According to the functional block diagram of FIG. 5E and FIGS. 1F and1G, a magnetic servo writer is disclosed in this invention. The magneticservo writer includes a magnetic pickup head for rotationally movingover and writing servo data in a magnetic flat data-storage medium. Themagnetic servo writer further includes a clock head for providing clocksignals to the clock head and to write clock signals in the magneticclock disk. The magnetic servo writer further includes a control circuitfor controlling the magnetic pickup head for writing the servo data onthe magnetic flat data-storage medium. The magnetic servo writer furtherincludes a servo pattern layout circuit for controlling the magneticpickup head for writing the servo data on the magnetic flat data-storagemedium with predefined servo patterns. The magnetic servo writer furtherincludes a derived index control circuit for deriving indices from afixed index provided on the magnetic flat data-storage medium. Themagnetic servo writer further includes a fixed index and clock trackcircuit for providing a fix index and a clock signal for controlling themagnetic pickup head for writing the servo data on the magnetic flatdata-storage medium. The magnetic servo writer further includes a headmove circuit for controlling a movement of the magnetic pickup head forwriting the servo data on the magnetic flat data-storage medium. Themagnetic servo writer further includes a medium movement circuit forcontrolling a linear movement of the magnetic flat data-storage mediumfor writing the servo data on the magnetic flat data-storage medium.

Therefore, the present invention discloses a data storage-card drivesystem with a pickup head moving above a data-storage card in rotationalmovement. The data read-write functions are enabled only for an arcsegment, e.g., half-circle, or several arc segments of the rotationalmovement. The data tracks are arranged as plurality of parallel arcs,e.g., half-circles, or arc-segments with uniform data bit storagedensity. Specifically, a pickup head is provided, which is driven by abrushless motor to rotate over the data-storage card. The motor ismounted on a carriage for making horizontal movement along alongitudinal direction of the data card. The position of the pickup headis then servo-controlled by moving the carriage and the brushless motorwhile the data storage card either stays at a fixed position or makingonly forward-backward movements. The difficulties and limitationsencountered in the prior art due to a non-uniform data storage densityamong different data tracks are resolved by this invention. Thetechnical difficulties caused by problems in loading/unloading of thepickup head to the recording medium, the transfer of read/write signalbetween the pickup head and the processing circuits, and the selfcentering of the data card in a data card drive device are also resolvedby this invention. Furthermore, the difficulty of positioning andlifting horizontal rotating pickup head parallel to a flat recordingsurface at any intermediate stop location to convert the signal from theflat card to parallel rotating pickup head to process circuit

Although the present invention has been described in terms of thepresently preferred embodiment, it is to be understood that suchdisclosure is not to be interpreted as limiting. Various alternationsand modifications will no doubt become apparent to those skilled in theart after reading the above disclosure. Accordingly, it is intended thatthe appended claims be interpreted as covering all alternations andmodifications as fall within the true spirit and scope of the invention.

We claim:
 1. A magnetic servo writer comprising: a single rotatingmagnetic pickup head for rotationally moving over and writing servo datain a magnetic flat data-storage medium for servo-controlling said singlerotating magnetic pickup head wherein said single rotating magneticpickup head is disabled during a specific range of rotational angularpositions when rotating over said data storage medium; and a lateralmovement means for moving said flat data-storage medium along lateraldirections substantially perpendicular to a rotational axis of saidsingle rotating pickup head.
 2. The magnetic servo writer of claim 1wherein: said single rotating magnetic pickup head is provided forwriting SYNC data for read channel synchronization for servo-controllingsaid single rotating magnetic pickup head.
 3. The magnetic servo writerof claim 1 wherein: said single rotating magnetic pickup head isprovided for writing ADM data for providing address mark for indicatingdata-types following said ADM data for servo-controlling said singlerotating magnetic pickup head.
 4. The magnetic servo writer of claim 1wherein: said single rotating magnetic pickup head is provided forwriting ST IDX data for indicating a first valid data segment forservo-controlling said single rotating magnetic pickup head.
 5. Themagnetic servo writer of claim 1 wherein: said single rotating magneticpickup head is provided for writing ED IDX data for indicating a lastvalid data segment for servo-controlling said single rotating magneticpickup head.
 6. The magnetic servo writer of claim 1 wherein: saidsingle rotating magnetic pickup head is provided for writing GRAY CODEdata for indicating a head number, a sector number, and a track numberfor servo-controlling said single rotating magnetic pickup head.
 7. Themagnetic servo writer of claim 1 wherein: said single rotating magneticpickup head is provided for writing SERVO POS data for indicating arelative position of said single rotating magnetic pickup head to a datatrack for servo controlling said single rotating magnetic pickup head.8. The magnetic servo writer of claim 1 wherein: said single rotatingmagnetic pickup head is provided for writing DATA & GAP data forindicating an area for containing pre-recorded data forservo-controlling said single rotating magnetic pickup head.
 9. Themagnetic servo writer of claim 1 wherein: said single rotating magneticpickup head is provided for writing index data for indicating a validdata track segment for servo-controlling said single rotating magneticpickup head.
 10. The magnetic servo writer of claim 1 furthercomprising: a control circuit for controlling said single rotatingmagnetic pickup head for writing said servo data on said magnetic flatdata-storage medium provided only to move along lateral directionssubstantially perpendicular to a rotational axis of said single rotatingpickup head.
 11. The magnetic servo writer of claim 1 furthercomprising: a servo pattern layout circuit for controlling said singlerotating magnetic pickup head for writing said servo data on saidmagnetic flat data-storage medium with predefined servo patterns forservo-controlling said single rotating magnetic pickup head.
 12. Themagnetic servo writer of claim 1 further comprising: a derived indexcontrol circuit for deriving indices from a fixed index provided on saidmagnetic flat data-storage medium provided only to move along lateraldirections substantially perpendicular to a rotational axis of saidsingle rotating pickup head.
 13. The magnetic servo writer of claim 1further comprising: a fixed index and clock track circuit for providinga fix index and a clock signal for controlling said single rotatingmagnetic pickup head for writing said servo data on said magnetic flatdata-storage medium provided only to move along lateral directionssubstantially perpendicular to a rotational axis of said single rotatingpickup head.
 14. The magnetic servo writer of claim 1 furthercomprising: a head move circuit for controlling a movement of saidsingle rotating magnetic pickup head for writing said servo data on saidmagnetic flat data-storage medium provided only to move along lateraldirections substantially perpendicular to a rotational axis of saidsingle rotating pickup head.
 15. The magnetic servo writer of claim 1further comprising: a medium movement circuit for controlling a linearmovement of said magnetic flat data-storage medium along lateraldirections substantially perpendicular to a rotational axis of saidsingle rotating pickup head for writing said servo data on said magneticflat data-storage medium.